Cross-thread-laying mechanism for sewing-machines.



N. D. CLARK.

CROSS THREAD LAYING MECHANISM FDR SEWING MACHINES.

APPLICATION FILED MAY 18. mm.

1,27 5,389. Tatented Aug. 13, 1918.

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N. 0. CLARK, I CROSS THREAD LAYING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED NIAY I8. 1916.

1,275,389. Patented Aug. 13, 1918.

4 SHEETS-SHEET 2.

N. D. CLARK. CROSS THREAD LAYING MECHANISM FOR SEWING MACHINES. APPLICATION FILED MAY1B.i916.

1 ,27 5,389 Patented Aug. 13, 1918.

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N. D. CLARK.

CROSS THREAD LAYING MECHANISM FOR SEWING MACHINES. APPLICATION FILED MAYIa. ma.

1,275,389. Patented .13; 191&

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UNITED STATES PATENT OFFICE.

NELSON D. CLARK, OF CHICAGO, ILLINOIS, ASSIGNOR TO UNION SI PEOIAL MACHINE COMPANY, OF CHICAGO, ILLINOIS. A CORPORATION OF ILLINOIS.

OROSS-IHREAD-LAYING MECHANISM FOR SEWING-MACHINES.

Application filed May 18, 1916. Serial No. 98,387.

To aZZ whom it may concern,-

Be it known that I, NnLsoND. CLARIQB. citizen of the United States, residing at Chicago, in the county of Cook, State of Illinois, have invented certain new and useful Improvements in Cross-Thread-Laying Mechanism for Sewing-Machines, of which the following is a description, reference being had to the accompanying drawing and to the figures of reference marked thereon.

My invention relates tonewand useful improvements in sewing machines, and more particularly to the thread laying mechanism for laying a thread on the upper face of the material so as to connect lines, of needle An object of the invention is to provide a thread laying mechanism for a pair of needles, wherein the thread is formed into loops by a reciprocating hook cooperating with a fixed thread guide, said reciprocating hook being carried by an oscillating member, the axis of which is relatively close to the hook so that said hook may cooperate with a fixed guide located slightly in rear of the needles, moved in front of both needles, and to a position relative to the farthest needle whereby the strand of the loop when positioned for the needle extending between the hook and the thread guide will, with certainty, be located between the needles.

A further object of the invention is to 7 provide a thread laying mechanism of the above character wherein the thread hook is mounted to swing about the center of the presser bar as an axis.

These and other objects will in part be obvious and will in part be hereinafter more fully disclosed.

In the drawings, which show'by way of illustration, one embodiment of the inven tion: v

Figure 1 is a view, partly in section and partly in side elevation, showing part of a sewing machine embodying my invention;

Fig. 2 is a vertical sectional view through the outer end of the overhanging arm, showing the manner of supporting the trimmer and the thread laying hook so that said parts swing about the presser bar as an axis;

Specification of Letters Patent.

fixed thread guide.

Patented Aug. 13, 1918.

Fig. 5'is a detail view in plan, showing the presser foot, the needles, the fixed thread guide and the movable thread hooks, said thread hooks being at the forward end of 7 their stroke;

Fig. 6 is a similar View, but with the thread hooks at the rear end of their stroke;

Fig. 7 is an enlarged view showing diagrammatically two fabric sections, the needles, the fixed thread guide and the hooks, withthe hooks at the rear end of their stroke; and

Fig. 8 is a similar view, but with the hooks at the forward end of theirstroke.

In carryingout my invention, I have provided a sewing machine having preferably two pairs of needles arranged in a line substantially at right angles tothe line of feed. A single looper cooperating respectively with the needles of each pair beneath the work support, joins'the needle threads so that fabric sections may have their edges abutted and said abutted edges connected by the stitching threads. Cooperating with each pair of needles above the work support is my improved thread laying mechanism which consists of a'fixed thread guide and a movable thread hook. The thread hook oscillates back and forth in a path extending in front of the needles and engages the thread extending between the fixed thread guide and the previously formed stitch and carries the same across the meeting edges of I the fabric sections forming a loop for the entrance of the needle farthest from the As the hook moves across the line of seam, the needles are up and the feed of the material takes place, and the cooperative action of the feed, the movable thread hook and the fixed thread guide positions the loop formed by the hook so that the strand of the loopextending from the hook to the previously formed stitch is located in rear of both needles, while the strand of the loop extending from the hook to the fixed thread guide is in front of the left hand needle or the needle farthest from the fixed guide and in rear of the right hand needle or the needle adjacent the fixed guide. After the needle has entered this loop, then the hook is retracted and the thread, after it passes through the fixed thread guide, is led through suitable guides in the shank or supporting arm for the movable thread hook, and said movable arm or shank takes up the slack in the cross thread drawing it around the needle.

Referring more in detail to the drawings I have shown the invention applied to a sewing machine having an overhanging arm 1 at the forward end of which is a reciprocating needle bar 2 carrying two pairs of needles 3-3 and 4-4. Cooperating with the needles 3-3 beneath the work support 5 is a looper 6, and cooperating with the nee dles 4-4 beneath the work support is a looper 7. Inasmuch as a single looper cooperates with each pair of needles, the l ooper thread will join the needle loops of the respective pair with which the looper cooperates.

The material to be stitched is held on the work support 5 by a presser foot 8 which is carried by a presser bar 9 mounted in suitable bearings 10 and 11 in the overhanging arm 1, see Fig. 2.

The work support, as herein shown, is in the form of a cylindrical arm and is shown as arranged in a plane at right angles to the plane of the overhanging arm. It is obvious, however, that my invention might be applied to other types of machines.

The material is fed off from the end of the work support by a feed dog 12, which feed dog is carried by a feed bar 13 operated as is usual in this type of machine.

As clearly shown in Fig. 5 of the draw ings, the presser foot is formed with a slot 14 which is adapted to receive the upturned edges of two fabric sections, and these edges are trimmed by trimming mechanism consisting of a fixed trimming blade15 and a movable trimming blade 16. After the edges are trimmed, they are brought into abutted relation and are joined by the stitching mechanism.

The presser foot is provided with an openmg 17 adapted to receive the needles 3-3. and a stitch tongue 18 projects between the needles, see Fig. 5. Said presser foot is also providedwith an opening 19 to receive the needles 4'4, and a stitch tongue 20 projects between this pair of needles.

The movable trimmer blade 16 is secured to an arm 21 carried by a collar 22 which is clamped at the lower end to a yoke 23 mounted to oscillate on the presser bar 9. Said yoke is yieldingly pressed downwardly by a spring 24 which bears at one end against the upper end of the yoke and at the other end against a collar 25 fixed to the presser bar 9. The downward movement of the yoke is limited by a collar 26 so positioned as to permit the movable blade to be held in shearing contact with the stationary blade. The yoke 23 is oscillated by a link 27 which is connected to the ball stud 2; attached to the yoke and to a ball stud 29 attached to an arm 30 carried by across shaft 31 at the rear of the machine, which cross shaft is oscillated by suitable devices driven from the main shaft of the machine.

Cooperating with the needles is a thread hook 32 and cooperating with the needles 44 is a. thread hook33. These thread hooks 32 and 33 are secured to an arm or shank 34 by suitable set-screws. The arm or shank 34 is connected or formed integral with a yoke which is mounted to swing about the axis of the presser bar 9. One arm of the yoke is located above the bearing 10 and the other arm is below said bearing sothat the yoke is held from endwise movement on the presser bar by this bearing. The yoke 35 is oscillated by a link 36 which is connected to a ball stud 37 carried by the yoke, and to a ball stud 38 carried by an arm 39 which is clamped to the shaft 31 so that, as the shaft 31 oscillates, the yoke 35 will be oscillated. There is a cross thread for each pair of needles and these cross threads areled through suitable guides 40 and 41 respectively formed in an arm 42 which is held in fixed position during the operation of the machine. Said arm is pivoted at 43 to a bracket 44 which, in turn. is secured to the overhanging arm by suitable screws 45. A spring 46 secured by a screw 47 to the arm 42 bears against a lug 48 on the bracket 44 and normally holds the arm in lowered position with the square shoulder 49 on the arm pressing against the lug. This spring permits the arm 42 to be turned to a substantially horizontal POSE' t-ion to permit the threading of the same or to give access to the needles for threading.

Referring to Figs. 7 and 8. .1 have shown two fabric sections A and B which have their edges abutted at C. The needles 3-? as shown in this figure. are so positionedthat the right hand needle enters the section B nearer the abutted edges C than the left hand needle, while the left hand needle 4 enters the section A at a point nearer the abutted edges than the right hand needle 4. This staggering of the needles 3-3 and 4-l causes the cross threads to overlap. This seam forms no part of my invention, and further description thereof is not thought necessary.

The cross thread a is laid about the needle thread loops formed by the needles 33, while the cross thread I) is laid about the needle thread loops formed by the needles l4. In Fig. 7 the hook32 is at the rear end of its stroke and is located close to the thread guide 40 for the cross thread (L. As the hook moves forwardly, it engages the cross thread and forms a loop in the cross thread, as shown in Fig. 8 where the hook is at the extreme forward end of its stroke. As the hook is moved forward, the feed of the fabric also occurs, and this carries the previous needle puncture and. previously formed needle loop in a rearward direction.

The fixed guide and the hook, when at the forward end of its stroke, are so positioned that the strand (1 formed in the cross thread a and extending from the hook to the thread guide 40 passes in front of the left hand needle 3 and in rear of the right hand needle 3. The strand a extending from the hook to the previous stitch a is in rear of 7 both needles andthus a loop isformed which receives the left hand needle 3. The forward movement of the hook also carries the cross thread around the needle loop a, when it moves forward, and this results in the laying of the cross thread back and forth around each needle loop. The cross thread 7) is engaged by the thread .hook 33 and manipulated in precisely thesame manner as described in connection with the cross thread a and hook 32. The cross threads at and 6 before passing through the thread guides 40 v and 41 are led through thread guides 48 and 49, respectively, formed in the arm or shank 34: which supports the thread hooks. These threads'a and I) also pass through the thread guide 50 on the overhanging arm. This positioning of the cross threads and the guides for directing the same, when the hooks are retracted, will pull on the cross threads and take up the slack, drawing the cross threads around the left hand needles. This insures, that'the cross thread will be laid without any undesirable slack back'and forth around the needle loops. 7 7

From the above description, it will be noted that the threadhooks and the trimmer are operated from the same shaft, that is, the cross shaft 31 at the rear of the machine, the yoke supporting the thread hook and the yoke supporting the trimmer are both mounted to oscillate about the axis of v the presser bar and the connecting devices for oscillating these yokes is so positioned relative to the axis of the presser bar that the trimmer moves forward for its trimming operation as the hooks are being retracted, and this gives the proper timed relation for the operating of the trimming mechanism relative to the operation of the stitching mechanism.

Furthermore, from the above description it will be apparent that the thread hook radius of swing of the "hookvery short,

this causes the hook to pass farther in front of the nearest needle and insures the hook clearing the same. Then again, by having a-short radius of swing for the hook, I am able to prevent overthrow of the hook and the pulling off of more thread than can be readily taken care of. A

It is obvious that minor changes in the details of construction may be made without departing from the'spir-it of the invention, as set forth in the appended claims.

Having thus described the invention, what is claimed as new is 1. The combination of a work support, a

resser bar feedin mechanism a air of.

. ing said thread hook whereby the samermay I swing about the center of the presser bar as an axis, said hook moving directly underneath the thread guide well infront of the needle adjacent thethread guide and to a position at one side of and in front of the needle farthest removed from the thread guide whereby the loop formed by the thread hook is properly positioned for the en trance only of the needle farthest from said thread guide.

2. The combination of a work support, feeding mechanism, a pair of needles arranged in a plane'at an angle to the line of feed, a stationary thread guide disposed at one side of the needles and in rear of the ad-v jacent needle, a thread'hook movable across thc'line of feed and adapted to engage the thread extending through said thread gulde and form a loop therein for the entrance of the needle farthest removed from said guide, said thread hook being movable to form the loop during the feeding action of the material whereby said feed, said thread hook and said fixed guide cooperate to position said loop with the strand extending from the hook to the previous stitch in rear of the needles and the strand extending from the hook to the fixed guide in rear of the needle adjacent the fixed guide and in front of the needle farthest from said fixed guide, an os cillating arm for supporting said thread hook, said arm having a thread guide for the cross thread passing through the fixed guide, and a fixed guide through which the cross thread is led to the thread guide in said arm whereby the backward movement of the thread hook causes said arm to pull on the cross thread and tighten the same around the needle. 7

3. The combination of a work support, feeding mechanism, a pair of needles arranged in a plane at an angle to the line of feed, a stationary thread guide disposed at one side of the needles and in rear of the adjacent needle, a thread carrier movable across the line of feed forengaging and forming a. loop in the cross thread passing through said stationary thread guide, said thread carrier operating to position said loop for the entrance of the needle farthest from the fixed thread guide, a presser foot, a presser bar supporting said presser foot, a yoke mounted to turn freely on the presser bar and carrying said thread carrier, and means for oscillating said yoke.

4. The combination of a work support, a

feeding mechanism, a pair of needles arranged in a plane substantially at right angles to the line of feed, a presser foot, a presser bar supporting the presser foot, a trimming mechanism including a horizontally moving trimming blade, a yoke sup porting said trimmer blade, said yoke being mounted to swing about the axis of the presser bar, a cross thread laying mechanism including a movable thread carrier, a yoke supporting said movable thread carrier, said last-named yoke being mounted to swing about the axis of the presser bar, and means for swinging said yokes.

5. The combination of a work support, a feeding mechanism, a pair of needles arranged in a plane substantially at right angles to the line of feed, a presser foot, a presser bar supporting the presser foot, a trimming mechanism including a horizontally moving trimming blade, a yoke supporting said trimming blade, said yoke being mounted to swing about the axis of the presser bar, a cross thread laying mechanism including a movable thread carrier, a yoke supporting said movable thread carrier, said last-named yoke being mounted to swing about the axis of the presser bar, a cross Copies of this patent may be obtained for said last-named arm to the yoke supporting the thread carrier.

6. The combination of a work support, feeding mechanism, a pair of needles arranged in a plane at an angle to the line of feed, a stationary thread guide disposed at one side of the needles and in rear of the plane of the needles, a thread carrier movable across the line of feed for engaging the thread passing through the thread guide and forming a loop for the entrance of the needle farthest removed from the guide, means-for supporting and oscillating. said thread carrier, said supporting meansbeing disposed relatively close to the needles whereby sa-idthread carrier moves in an are having a relatively short radius sothat said book may pass underneath the thread guide well in front of the needle "adjacent the thread guide and to a point at one side of and in front of the needle farthest from the thread guide so that the strand of the loop carried by the thread carrier extending from the hook to the thread guide may pass between the needles.

7. The combination of a work support, feeding mechanism, 'a pair of needles arranged in a plane at an angle to the line of feed, a stationary thread guide disposed at one side of the needles andin rear of the plane of the needles, a thread hook movable across the line of feed and adapted to engage the thread extending through said thread guide and form a loop therein for from said guide, a supporting arm for said thread hook, said supporting arm having an eye for the thread engaged by the thread hook and'devices for guiding said thread to the arm, said devices being so disposed that a backward movement of said arm draws the thread around the needle.

In testimony whereof I affix my signature in the presence of two witnesses.

NELSON D. CLARK. Witnesses:

S. Gnonen TATE, JOHN E. OHALMAN.

five cents each,- by addressing the Commissioner of Patents,

Washington, D. 0.

the entrance of the needle farthest removed I 

